Semiconductor package electrical contacts and related methods

ABSTRACT

Implementations of a semiconductor package may include a semiconductor die including a first side and a second side, the first side of the semiconductor die including one or more electrical contacts; and an organic material covering at least the first side of the semiconductor die. Implementations may include where the one or more electrical contacts extend through one or more openings in the organic material; a metal-containing layer coupled to the one or more electrical contacts; and one or more slugs coupled to one of a first side of the semiconductor die, a second side of the semiconductor die, or both the first side of the semiconductor die and the second side of the semiconductor die.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of the earlier U.S. UtilityPatent Application to Eiji Kurose entitled “Semiconductor PackageElectrical Contacts and Related Methods,” application Ser. No.16/861,910, filed Apr. 29, 2020, now pending, which application is acontinuation-in-part application of the earlier U.S. Utility PatentApplication to Eiji Kurose entitled “Multi-Faced Molded SemiconductorPackage and Related Methods,” application Ser. No. 16/702,958, filedDec. 4, 2019, now issued as U.S. Pat. No. 11,328,930; which was adivisional application of the earlier U.S. Utility Patent Application toEiji Kurose entitled “Multi-Faced Molded Semiconductor Package andRelated Methods,” application Ser. No. 15/679,661, filed Aug. 17, 2017,issued on Jan. 7, 2020 as U.S. Pat. No. 10,529,576, the disclosures ofeach of which are hereby incorporated entirely herein by reference.

The Ser. No. 16/861,910 application is also a continuation-in-partapplication of the earlier U.S. Utility Patent Application to Lin etal., entitled “Thinned Semiconductor Package and Related Methods,”application Ser. No. 15/921,898, filed Mar. 15, 2018, now issued as U.S.Pat. No. 10,748,850, the disclosure of which is hereby incorporatedentirely herein by reference.

BACKGROUND 1. Technical Field

Aspects of this document relate generally to semiconductor packages,such as chip scale packages and flip chip packages. More specificimplementations involve semiconductor packages covered by a moldcompound.

2. Background

Decreasing semiconductor package size has long been desirable within theindustry as it has generally resulted in economic benefits as well astechnological benefits. A decrease in semiconductor package size oftenresults in an increase in risk of damage to the semiconductor die andpackage during manufacturing. A protective cover or molding hasgenerally covered portions of the semiconductor packages to protect thesemiconductor from, among other things, the environment, electrostaticdischarge, and electrical surges.

SUMMARY

Implementations of a semiconductor package may include a semiconductordie including a first side and a second side, the first side of thesemiconductor die including one or more electrical contacts; and anorganic material covering at least the first side of the semiconductordie. Implementations may include where the one or more electricalcontacts extend through one or more openings in the organic material; ametal-containing layer coupled to the one or more electrical contacts;and one or more slugs coupled to one of a first side of thesemiconductor die, a second side of the semiconductor die, or both thefirst side of the semiconductor die and the second side of thesemiconductor die.

Implementations of semiconductor packages may include one, all, or anyof the following:

The one or more slugs may be coupled directly to the metal-containinglayer.

The one or more electrical contacts comprise a bump coupled to a die padcoupled to the first side of the semiconductor die.

The organic material may be a mold compound.

The metal-containing layer may be a solder resist layer.

The semiconductor die may include a thickness between 0.1 microns and125 microns.

The one or more electrical contacts may be one of bumps or studs, thesecond side of the die further may include a backmetal, and the one ormore slugs may be coupled to the backmetal.

Implementations of a method of forming a semiconductor package mayinclude providing a semiconductor substrate including a plurality ofsemiconductor die, the semiconductor substrate including a first sideand a second side; and forming one or more electrical contacts on thefirst side of the semiconductor die, the one or more electrical contactscoupled with the plurality of semiconductor die. Implementations mayinclude applying an organic material to the first side of thesemiconductor die. The one or more electrical contacts may extend intoone or more openings in the organic compound. Implementations mayinclude leveling the organic material with a surface of the one or moreelectrical contacts; and directly coupling one or more slugs to one ormore of the one or more electrical contacts or to the second side of thesemiconductor substrate.

Implementations of a method of forming a semiconductor package mayinclude one, all, or any of the following:

The one or more slugs may be coupled directly to a metal-containinglayer comprised in the one or more electrical contacts.

The metal-containing layer may be a solder resist material.

The one or more electrical contacts may be coupled to a pad comprised inthe plurality of semiconductor die.

Implementations of the method may include grooving a surface of thesemiconductor substrate at a plurality of die streets between theplurality of semiconductor die.

Implementations of the method may include forming a backmetal on thesecond side of the semiconductor substrate.

Implementations of the method may include directly coupling the one ormore slugs to the backmetal.

Implementations of the method may include thinning the semiconductorsubstrate to a thickness of 0.1 microns to 125 microns.

The plurality of electrical contacts may be one of bumps or studs thatextend above the organic material and the one or more slugs may bedirectly coupled with the second side of the semiconductor substrate.

Implementations of a method of forming a semiconductor package mayinclude providing a semiconductor substrate including a plurality ofsemiconductor die, the semiconductor substrate including a first sideand a second side; forming one or more electrical contacts on the firstside of the semiconductor die by forming at least a portion of the oneor more electrical contacts to a predetermined height, the one or moreelectrical contacts coupled with the plurality of semiconductor die.Implementations may include applying an organic material to the firstside of the semiconductor die. The one or more electrical contacts mayextend into one or more openings in the organic compound.Implementations of the method may include leveling the organic materialwith a surface of the one or more electrical contacts. The predeterminedheight of the formed portion of the one or more electrical contacts mayreduce warpage of the semiconductor package to below 200 microns.

Implementations of a method of forming a semiconductor package mayinclude one, all, or any of the following:

Forming the one or more electrical contacts may include electroplating.

Forming the plurality of electrical contacts may include evaporating,sputtering, soldering, screen printing, silver sintering and anycombination thereof.

The organic material may be a mold compound.

The foregoing and other aspects, features, and advantages will beapparent to those artisans of ordinary skill in the art from theDESCRIPTION and DRAWINGS, and from the CLAIMS.

BRIEF DESCRIPTION OF THE DRAWINGS

Implementations will hereinafter be described in conjunction with theappended drawings, where like designations denote like elements, and:

FIG. 1 is a cross sectional side view of a semiconductor package;

FIG. 2 is a top view of a semiconductor package;

FIG. 3 is a first process flow illustrating the formation of asemiconductor package;

FIG. 4 is a top view of a semiconductor wafer with a plurality ofnotches cut therein;

FIG. 5 is a top view of a semiconductor wafer with a plurality ofnotches etched therein;

FIG. 6 is a top view of a second implementation of a semiconductor waferwith a plurality of notches etched therein;

FIG. 7 is a top view of a third implementations of a semiconductor waferwith a plurality of notches etched therein;

FIG. 8 is a cross sectional view of a portion of a wafer with moldingapplied thereto;

FIG. 8A is a magnified cross sectional view of the bond between a moldand a sidewall of a notch formed in the die;

FIG. 9 is a second process flow illustrating the formation of asemiconductor package;

FIG. 10 is a third process flow illustrating a portion of the formationof a semiconductor package.

FIG. 11 illustrates a first alternative for forming the notches in thethird process flow.

FIG. 12 illustrates a second alternative for forming the notches in thethird process flow;

FIG. 13 illustrates a third alternative for forming the notches in thethird process flow;

FIG. 14 illustrates a fourth alternative for forming the notches in thethird process flow;

FIG. 15 is a fourth process flow illustrating the formation of asemiconductor package;

FIG. 16 is a cross-section side view of an implementation of asemiconductor package;

FIG. 17 is a cross-section side view of another implementation of asemiconductor package;

FIGS. 18A-18G are cross-section side views illustrating a semiconductordevice following various steps of a method for forming the semiconductorpackage of FIG. 16;

FIGS. 19A-19C are cross-section side views of a semiconductor devicefollowing various steps of a method for forming the semiconductorpackage of FIG. 17;

FIG. 20 is a cross-section side view of an implementation of asemiconductor package with lengthened electrical contacts;

FIG. 21 is a cross-section side view of an implementation of asemiconductor package with a slug coupled to an electrical contact;

FIG. 22 is a cross-section side view of an implementation of asemiconductor package with a slug coupled to backmetal;

FIGS. 23A-G are cross-section side views illustrating a semiconductorpackage following various steps of a method for forming thesemiconductor package of FIG. 21; and

FIGS. 24A-C are cross-section side views illustrating a semiconductorpackage following various steps of a method for forming thesemiconductor package of FIG. 22.

DESCRIPTION

This disclosure, its aspects and implementations, are not limited to thespecific components, assembly procedures or method elements disclosedherein. Many additional components, assembly procedures and/or methodelements known in the art consistent with the intended semiconductorpackage will become apparent for use with particular implementationsfrom this disclosure. Accordingly, for example, although particularimplementations are disclosed, such implementations and implementingcomponents may comprise any shape, size, style, type, model, version,measurement, concentration, material, quantity, method element, step,and/or the like as is known in the art for such semiconductor packages,and implementing components and methods, consistent with the intendedoperation and methods.

Referring to FIG. 1, a cross sectional side view of a semiconductorpackage is illustrated. The semiconductor package includes a die 2 whichincludes a first side 4, a second side 6, a third side 8 opposite thesecond side 6, a fourth side, a fifth side opposite the fourth side(both fourth and fifth sides are located into and out of the drawingsurface in this view), and a sixth side 10 opposite the first side 4. Invarious implementations, the second side 6 of the die 2, the third side8 of the die, the fourth side of the die, and/or the fifth side of thedie may include a notch therein.

In various implementations, one or more electrical contacts 12 arecoupled to the first side 4 of the die 2. In various implementations,the electrical contacts are metal and may be, by non-limiting example,copper, silver, gold, nickel, titanium, aluminum, any combination oralloy thereof, or another metal. In still other implementations, theelectrical contacts 12 may not be metallic but may rather be anotherelectrically conductive material.

In various implementations, a first mold compound 14 covers the first,second, third, fourth, and fifth sides of the die. In variousimplementations, the mold compound may be, by non-limiting example, anepoxy mold compound, an acrylic molding compound, or another type ofmaterial capable of physically supporting the die and providingprotection against ingress of contaminants. In various implementations,a laminate resin or second mold compound covers the sixth side 10 of thedie.

The electrical contacts 12 each extend through a corresponding pluralityof openings in the first mold compound 14. In various implementations,the electrical contacts 12 extend beyond the surface of the molding 14,as illustrated in FIG. 1, while in other implementations the electricalcontacts are level or flush with the surface of the molding compound 14.

In various implementations, the sides of the die will have no chips orcracks, particularly on the semiconductor device side of the die. Thisis accomplished through forming the second, third, fourth, and fifthsides of each die using etching techniques rather than a conventionalsawing technique. Such a method is more fully disclosed is associationwith the discussion of FIG. 3 herein.

Further, the first mold compound may be anchored to the second, third,fourth, and fifth sides of the die. In various implementations, theanchor effect is the result of interaction of the mold compound with aplurality of ridges formed along the second, third, fourth, and fifthsides of the die. This anchoring effect is more fully disclose inassociation with the discussion of FIG. 3 herein.

Referring to FIG. 2, a top view of a semiconductor package isillustrated. The molding compound 14 is clearly seen in FIG. 2encompassing a perimeter of each electrical contact 12 (the shaded areasin FIG. 2) so that the entire first side of the die (along with everyother side) is not exposed.

Referring to FIG. 3, a first process flow illustrating the formation ofa semiconductor package is illustrated. In various implementations, themethod for making a semiconductor package includes providing a wafer 16which may include any particular type of substrate material, including,by non-limiting example, silicon, sapphire, ruby, gallium arsenide,glass, or any other semiconductor wafer substrate type. In variousimplementations, a metal layer 18 is formed on a first side 28 of thewafer 16 and may be formed using a sputtering technique. In otherimplementations, the metal layer 18 is formed using other techniques,such as, by non-limiting example, electroplating, electroless plating,chemical vapor deposition, and other methods of depositing a metallayer. In a particular implementation, the metal layer is atitanium/copper seed layer, while in other implementations, the metallayer may include, by non-limiting example, copper, titanium, gold,nickel, aluminum, silver, or any combination or alloy thereof.

In various implementations, a first photoresist layer 20 is formed andpatterned over the metal layer 18. One or more electrical contacts 22may be formed on the metal layer 18 and within the photoresist layer 20.In various implementations this may be done using various electroplatingor electroless plating techniques, though deposition and etchingtechniques could be employed in various implementations. The electricalcontacts 22 may be any type of electrical contact previously disclosedherein (bumps, studs, and so forth). In various implementations, thefirst photoresist layer 20 is removed through an ashing or solventdissolution process and the metal layer 18 may be etched away after theelectrical contacts are formed.

In various implementations, a second photoresist layer 24 is formed andpatterned over the wafer 16. In various implementations, as illustratedin FIG. 3, the second patterned photoresist layer 24 does not cover theelectrical contacts 22. In other implementations, the second photoresistlayer is formed conformally over the electrical contacts along with thewafer. Referring to FIG. 9, a second process flow illustrating theformation of a semiconductor package is illustrated. In this processflow, a second photoresist layer 68 is formed as a conformal layer overthe electrical contacts 70. Aside from this difference, the processdepicted in FIG. 9 includes the same process steps as the processdepicted in FIG. 3.

Referring back to FIG. 3, in various implementations, the methodincludes etching a plurality of notches 26 into the first side 28 of thewafer 16 using the second patterned photoresist layer. In variousimplementations, the width of the notches may be between about 50 andabout 150 microns wide while in other implementations, the width of thenotches may be less than about 50 microns or more than about 150microns. In various implementations, the depth of the plurality ofnotches 26 may extend between about 25 and 200 microns into the waferwhile in other implementations, the depth of the plurality of notches 26may be less than about 25 microns or more than about 200 microns.

In various implementations, the plurality of notches may be formedusing, by non-limiting example, plasma etching, deep-reactive ionetching, or wet chemical etching. In various implementations, a processmarketed under the tradename BOSCH® by Robert Bosch GmbH, StuttgartGermany (the “Bosch process”), may be used to form the plurality ofnotches 26 in the first side 28 of the wafer 16.

Referring now to FIG. 4, a top view of a conventional semiconductorwafer with a plurality of saw cuts surrounding the plurality of die isillustrated. Using a saw to cut notches in a semiconductor waferinvariably results in the production of chips and cracks on the deviceside of the die and in the sidewalls 34 of the notches 30. The presenceof the cracks and chips has the potential to compromise the reliabilityof the semiconductor package if the cracks and chips propagate into thedevice portion of the semiconductor die. Since the saw process involvesthe rubbing of the rotating blade against the die surface, the chippingand cracking can only be managed through saw processing variables (waferfeed speed, blade kerf width, cut depth, multiple saw cuts, bladematerials, etc.) but not eliminated. Furthermore, because the sawprocess relies on passing the wafer underneath the blades, only squareand rectangular sized die are typically produced using conventional sawtechniques.

Referring to FIG. 5, a top view of a semiconductor wafer with aplurality of notches etched therein is illustrated. In contrast to theappearance of the die processed using the conventional sawing methodillustrated in FIG. 4, the plurality of notches 36 in the wafer 38formed using etching techniques have edges and sidewalls 40 that do notexhibit cracks or chips therein. Because of the absence of the cracksand chips, the use of etching techniques to form a plurality of notchesin a semiconductor wafer is likely to improve the reliability of theresulting semiconductor packages.

Furthermore, using etching techniques to form a plurality of notches ina wafer allows for different shapes of perimeters of die to be produced.In various implementations, the second photoresist layer described inrelation to FIG. 3 may be patterned in a way to form a plurality ofnotches that do not form die with rectangular perimeters. For example,referring to FIG. 6, a top view of a second implementation of asemiconductor wafer with a plurality of notches etched therein isillustrated. In various implementations, a plurality of notches 42 maybe formed in a wafer 44. The plurality of notches 42 may form eventualdie 46 with perimeters that are octagons. Referring to FIG. 7, a topview of a third implementations of a semiconductor wafer with aplurality of notches etched therein is illustrated. In variousimplementations, a plurality of notches 48 may be formed in a wafer 50.The plurality of notches 48 may form eventual die 52 with perimetersthat are rounded rectangles. In other implementations, a plurality ofnotches may be formed in a wafer that form eventual die with perimetersthat are any other closed geometrical shape.

Referring back to FIG. 3, in various implementations, the plurality ofnotches 26 formed have two substantially parallel sidewalls that extendsubstantially straight into the first side 28 of the wafer 16. In otherimplementations, two or more stepwise notches are formed in the firstside 28 of the wafer 16. Each stepwise notch may be formed by creating afirst notch in the wafer, and then forming a second more narrow notchwithin each first notch.

Referring to FIG. 3, an implementation of a method for forming asemiconductor package includes applying a first mold compound 54 intothe plurality of notches 26 and over the first side of the wafer. Invarious implementations, as illustrated by FIG. 3, the first moldcompound 54 may cover the electrical contacts 22. In otherimplementations, the first mold compound 54 may not completely cover theelectrical contacts 22. The first mold compound may be applied using, bynon-limiting example, a liquid dispensing technique, a transfer moldingtechnique, a printer molding technique, or a compression moldingtechnique. The molding compound may be an epoxy molding compound, anacrylic molding compound, or another type of molding compound disclosedherein.

In various implementations, the first mold compound 54 may be anchoredto a plurality of sidewalls 56 of a plurality of notches 26. Referringnow to FIG. 8, a cross sectional view of a portion of a wafer withmolding applied thereto is illustrated. Referring now to FIG. 8A, amagnified cross sectional view of the bond between a mold and a sidewallof a notch formed in the die is illustrated. In various implementations,a plurality of ridges 58 may be formed in a sidewall 56 of each notchwithin the plurality of notches. In a particular implementation, theheight of each ridge extending from the sidewall is substantially 0.2microns tall with a pitch of substantially one micron. Thus, inimplementations where the notch is 150 microns deep, there may besubstantially 150 microns on each sidewall of the notch. In otherimplementations, the notches may be taller or shorter than 0.2 micronsand may have a pitch more or less than one micron. The ridges may anchorthe first mold compound 54 to the sidewalls 56 of the plurality ofnotches. In various implementations where the plurality of notches areetched using the Bosch process, the etching process may form ridges inthe plurality of notches while etching the plurality of notches via thedeposition/etching cycles of the deep reactive ion etch, thus increasingthe adhesion between the first mold compound and the sidewall of eachnotch.

Referring back to FIG. 3, in various implementations where the firstmold compound 54 covers the electrical contacts 22, the electricalcontacts 22 may be exposed by grinding the first mold compound. Invarious implementations, a second side 60 of the wafer 16 may be groundto the plurality of notches 26 formed in the first side 28 of the wafer16. In this way the various die of the semiconductor wafer aresingulated from each other. In various implementations, the second side60 of the wafer 16 may be ground using, by non-limiting example, amechanical polishing technique, a chemical etching technique, acombination of a mechanical polishing and chemical etching technique, orany other grinding technique.

In various implementations, a second mold compound 62 or a laminateresin may be applied to the second side 60 of the wafer 16. Inimplementations where a second mold compound is applied, the moldcompound may be any type of mold compound disclosed herein and may beapplied using any technique disclosed herein.

In various implementations, as illustrated in the process flow depictedin FIG. 3, the first mold compound 54 is ground to expose the electricalcontacts 22 before the second side 60 of the wafer 16 is ground and thesecond mold compound is applied. In other implementations, the firstmold compound 54 may be ground to expose the electrical contacts 22after the second side 60 of the wafer 16 is ground and the second moldcompound is applied.

The method for making a semiconductor package includes singulating thewafer 16 into a plurality of semiconductor packages 64. The wafer 16 maybe singulated by cutting or etching through the wafer where theplurality of notches 26 were originally formed. The wafer may besingulated by using, by non-limiting example, a saw, a laser, awaterjet, plasma etching, deep reactive-ion etching, or chemicaletching. In various implementations, the Bosch process may be used tosingulate the wafer 16. The method used to singulate the wafer mayinclude singulating the wafer using thinner cuts or etches than wereused to form the plurality of notches 26. In this manner, the first moldcompound will cover the sides of each singulated die 66 within eachsemiconductor package 64. Specifically, in particular implementationsthe saw width used to singulate each semiconductor package may bebetween 20 and 40 microns thick. The semiconductor die within thesemiconductor package may be covered by either a mold compound or alaminate resin on all six sides of the semiconductor die.

In various implementations, the first side of the die within eachsemiconductor package may include a perimeter that is, by non-limitingexample, a rectangle, an octagon, a rectangle with rounded edges, or anyother closed geometric shape.

Referring now to FIG. 10, a third process flow illustrating a portion ofthe formation of a semiconductor package is illustrated. In variousimplementations the method for forming a semiconductor package includesproviding a wafer 72, which may be any type of wafer substrate disclosedherein. In various implementations, one or more metal pads 74 may becoupled to a first side 76 of the wafer 72. The metal pad may include,by non-limiting example, aluminum, copper, nickel silver, gold,titanium, or any combination or alloy thereof.

In various implementations, a first passivation layer 78 may be coupledto a portion of the first side 76 of the wafer 72. The first passivationlayer 78 may be a silicon dioxide passivation layer in variousimplementations, though it could be any of a wide variety of other typesof layers, including, by non-limiting example, silicon nitride,polyimide, or another polymer or deposited material. In variousimplementations, a second passivation layer 80 may be coupled to aportion of the first side 76 of the wafer 72. The second passivationlayer 80 may be a silicon nitride passivation layer. The secondpassivation layer may include the same material or a different materialfrom the first passivation layer.

In various implementations, a third layer 82 may be coupled to a portionof the first side 76 of the wafer 72. The third layer may be either apolyimide, a polybenzoxazole, a phenol resin, or a combination of apolyimide, a polybenzoxazole, and a phenol resin. In variousimplementations, a metal seed layer 84 may be formed over the thirdlayer and over the first side 76 of the wafer 72. The metal seed layer84 may be any type of metal layer disclosed herein. In variousimplementations, the metal seed layer 84 may directly contact portionsof the first side 76 of the wafer 72. In various implementations, themethod includes forming and patterning a first photoresist layer 86 overthe metal seed layer 84.

In various implementations, the method includes forming electricalcontacts 88 coupled to the metal seed layer 84 and within the firstphotoresist layer 86. The electrical contacts 88 may be any type ofelectrical contact disclosed herein. In various implementations, theelectrical contacts 88 may include a first layer 90 and a second layer92. In various implementations, the first layer 90 may include copperand the second layer 92 may include tin, silver, or a combination of tinand silver. In various implementations, the method of forming asemiconductor package includes removing the first photoresist layer 86and etching the portions of the metal seed layer 84 away that are notcovered by the electrical contacts, after the electrical contacts areformed.

In various implementations, the method of forming a semiconductorpackage includes forming and patterning a second photoresist layer 94over the first side 76 of the wafer 72. In various implementations, thesecond photoresist layer covers the electrical contacts 88, while inother implementations, the second photoresist layer 94 does not coverthe electrical contacts 88. The second photoresist layer 94 may be usedto etch a plurality of notches 96 into the wafer 72. The method includesremoving the second photoresist layer 94 after the plurality of notchesare etched into the wafer.

A first mold compound may be applied into the plurality of notches andover the first side 76 of the wafer 72 in the same manner the first moldcompound in FIG. 3 is applied. The remainder of the method for forming asemiconductor package as depicted in FIG. 10 may include exposing theelectrical contacts through grinding, grinding the backside of the waferto the plurality of notches, applying a second mold compound or laminateresin to a backside of the wafer, and singulating the wafer into aplurality of semiconductor packages. These portions of forming asemiconductor package may be the same as or similar to respectiveportions for forming a semiconductor package illustrated by FIG. 3 andpreviously disclosed herein.

In various implementations, the semiconductor package produced by themethod depicted in FIG. 10 may include one or more metal pads, one ormore passivation layers, a polyimide, a phenol resin, a polybenzoxazole,and any combination thereof, between the semiconductor die and the firstmold compound.

Referring to FIGS. 11-14, alternative methods for forming a plurality ofnotches in the process illustrated by FIG. 10 is illustrated. Referringto FIG. 11, a method of forming a plurality of notches using a patternedphotoresist layer and one of a polyimide, polybenzoxazole, and a phenolresin in combination with an etching process is illustrated. In variousimplementations, a patterned photoresist layer 98 may be over a mask 100including either a patterned polyimide layer, a patternedpolybenzoxazole layer, or a patterned phenol resin layer. The mask 100may be over a wafer 102. A notch 104 may be formed in the wafer 102using the patterned photoresist layer and the mask using any etchingprocess disclosed herein.

Referring to FIG. 12, a method of forming a plurality of notches usingone of a polyimide, polybenzoxazole, and a phenol resin in combinationwith any etching process disclosed herein is illustrated. The method maybe the same as the method depicted by FIG. 11, with the difference beingthat the method depicted by FIG. 12 does not include a patternedphotoresist layer used to form a notch 106 into a wafer 108.

Referring to FIG. 13, a method of forming a plurality of notches using apatterned photoresist layer and passivation mask is illustrated. Invarious implementations, a patterned photoresist layer 110 may be over apassivation mask 112. The passivation mask 112 may include anypassivation layer disclosed herein. The passivation mask 112 may be overa wafer 114. A notch 116 may be formed in the wafer 114 using thepatterned photoresist layer 110 and the passivation mask 112 and anyetching process disclosed herein.

Referring to FIG. 14, a method of forming a plurality of notches using apassivation mask in combination with any of the etching method disclosedherein is illustrated. The method may be the same as the method depictedby FIG. 13, with the difference being that the method depicted by FIG.14 does not include a patterned photoresist layer used to form a notch116 into a wafer 118.

Referring to FIG. 15, a fourth process flow illustrating the formationof a semiconductor package is illustrated. The method for forming asemiconductor package illustrated in FIG. 15 includes providing a wafer120. In various implementations, an interlayer 122 may be coupled to afirst side 124 of the wafer 120. In various implementations, apassivation layer 128 may be coupled to the wafer 120. The passivationlayer may be any type of passivation layer disclosed herein.

In various implementations, one or more electrical contacts 126 may becoupled to the wafer 120. In various implementations, the electricalcontacts include a bump 130. The electrical contacts may include a firstmetal layer 132 coupled to the bump 130. The first metal layer mayinclude any metal disclosed herein. In a particular implementation, thefirst metal layer includes nickel and gold. The electrical contacts 128may include a second metal layer 134 coupled to the first metal layer132. The second metal layer 134 may include any metal disclosed herein.In a particular implementation, the second metal layer 134 includesaluminum. In various implementations, a solder resist layer 136 may becoupled over the wafer 120. In other implementations, no solder resistlayer is included.

In various implementations, the passivation layer 128 may be patternedand may directly contact portions of the wafer 120. In suchimplementations, the patterned passivation layer, or mask, may be usedto etch a plurality of notches 138 into the first side 124 of the wafer120 using any etching process disclosed herein. The plurality of notchesmay be etched using any method disclosed herein, and may be any type ofnotch previously disclosed herein.

In various implementations, a first mold compound 140 is applied intothe plurality of notches 138 and over the first wafer 120. The firstmold compound 140 may be any mold compound disclosed herein and may beapplied using any technique disclosed herein. In variousimplementations, the first mold compound 140 does not entirely cover theelectrical contacts 126, as is illustrated by FIG. 15. In otherimplementations, the first mold compound does entirely cover theelectrical contacts 126. In implementations where the first moldcompound 140 does entirely cover the electrical contacts 126, the firstmold compound may be ground to expose the electrical contacts 126.

In various implementations, a second side 142 opposite the first side124 of the wafer 120 may be ground using any grinding method disclosedherein to the plurality of notches. A second mold compound 144 orlaminate resin may then be applied to the second side 142 of the wafer120.

The wafer 120 may then be singulated into a plurality of semiconductorpackages 146. The wafer may be singulated using any technique disclosedherein. The semiconductor die 148 with the semiconductor package 146 mayhave all six sides covered by a mold compound. In other implementations,the sixth side of the die 150 may be covered by a laminate resin.

In various implementations, the semiconductor package formed by themethod illustrated in FIG. 15 may include either a solder resist layer,a passivation layer, an interlayer, or a combination of a solder resistlayer, a passivation layer, and an interlayer coupled to the first sideof the wafer and covered by the first mold compound.

Referring to FIG. 16, a cross-section side view of an implementation ofa semiconductor package is illustrated. In various implementations, thesemiconductor packages disclosed herein may include power semiconductordevices, however, in other implementations other semiconductor devicetypes (transistors, microprocessors, passive components, etc.) may beincluded in the semiconductor packages. In various implementations, thesemiconductor package 152 includes a die 154. The die 154 may be asilicon die, and in such implementations, the silicon die could be anytype of silicon die including, by non-limiting example, an epitaxialsilicon die, silicon-on-insulator, polysilicon, any combination thereof,or any other silicon-containing die material. Further, it is alsounderstood that in various implementations a die other than asilicon-containing die may be used, such as, by non-limiting example,gallium arsenide, silicon carbide, gallium arsenide, or ametal-containing die. The die 154 has a first side 156 and a second side158 opposite the first side. In various implementations, the thicknessof the die 154 is less than 50 micrometers (um), however, in otherimplementations the thickness of the die may be 50 um or more than 50um.

In various implementations, the semiconductor package 152 may include afirst metal layer 160 coupled to the first side 156 of the die 154. Insuch implementations, the first metal layer 160 may be, by non-limitingexample, copper, aluminum, tin, silver, gold, titanium, nickel, or anyother metal or metal alloy. In various implementations, the first metallayer 160 may be directly coupled to the first side 156 of the die 154,while in other implementations, as is illustrated by FIG. 16, the firstmetal layer may be indirectly coupled to the die 154. In variousimplementations, the semiconductor package 152 may include a tin layer162 coupled to the first metal layer 160. While this disclosureprimarily refers to a tin layer coupled over the first metal layer, itis understood that any other electrically and/or thermally conductivematerial, including any metal or metal alloy disclosed herein, may beused in place of the tin. Also, the tin used in the tin layer may be tinor a tin alloy, such as, by non-limiting example, tin/silver,tin/silver/copper, tin/antimony, and tin/lead. In variousimplementations, and as illustrated by FIG. 16, the tin layer 162 may bedirectly coupled to the first metal layer 160 with the first metal layer160 between the tin layer and the die 154. In other implementations thetin layer 162 may be indirectly coupled to the first metal layer 160.

In various implementations, the semiconductor package 152 may include asecond metal layer 164 coupled between the die 154 and the first metallayer 160. In such implementations, the semiconductor package 152includes at least three metal layers over the die 154. The second metallayer 164 may be any type of metal or metal alloy disclosed herein. Inparticular implementations, the second metal layer may include tin or atin alloy, such as, by non-limiting example, tin/silver,tin/silver/copper, tin/antimony, and tin/lead. In other particularimplementations, the second metal layer 164 may include aluminum, thefirst metal layer 160 may include copper, and the tin layer 162 may beover and coupled to the copper layer.

In various implementations, the tin layer 162 and the first metal layer160 may be formed into and include a plurality of bumps/studs 166. Inimplementations including a second metal layer 164 between the firstmetal layer 160 and the die 154, the second metal layer 164 may also bepatterned to form a portion of the plurality of bumps 166. In particularimplementations, not all three metal layers are patterned to form aplurality of bumps, but only the two outermost metal layers (inimplementations having three or more metal layers over the die 154)include the plurality of bumps. In still other implementations, only thetin layer 162 may be patterned to form or include the plurality ofbumps. In various implementations, and as illustrated by FIG. 16, theplurality of bumps 166 may include two bumps, however, in otherimplementations the plurality of bumps may include more than two bumps.

In various implementations, rather than having a plurality of metallayers forming the bumps as illustrated by FIG. 16, a single metal ormetal alloy layer, including, by non-limiting example, copper, aluminum,tin, a solder, or any combination thereof, may form the plurality ofbumps and may be directly coupled to the die 154. In otherimplementations, and as illustrated by FIG. 16, each bump of theplurality of bumps 166 may include multiple layers with a tin layer 162coupled over the copper layer. In such implementations, thesemiconductor package 152 may have the benefit of being able to bond toexternal connections through the tin layer 162 while also maintainingthe benefit of having a copper bump or stud. In various implementations,the tin layer 162 may be much thinner than the first metal layer 160,while in other implementations, the tin layer 162 may be as thick as orthicker than the first metal layer 160. In implementations with a secondmetal layer 164 coupled between the first metal layer 160 and the die154, the second metal layer may be less thick, as thick, or more thickthan the first metal layer when viewed in a cross sectional view of thedie 154.

In various implementations, the semiconductor package 152 may include abackside metal layer 168 coupled to the second side 158 of the die 154.The backside metal layer 168 may be any metal disclosed herein, and invarious implementations, may include copper. In particularimplementations, the backside metal layer may include, by non-limitingexample, Ti/Ni/Cu, Ti/Cu, TiW/Cu, or any other type of metal stack ormetal alloy including copper. In various implementations, and asillustrated by FIG. 16, the length of the backside metal layer 168 maybe less than the length of the die 154. In such implementations, the die154 may overhang the backside metal layer 168. In other implementations,the length of the backmetal layer 168 may be substantially the same asthe length of the die 154 with the sides of the backmetal layercoextensive with the sides/perimeter of the die. In still otherimplementations, the back metal layer may extend beyond thesides/perimeter of the die 154. In various implementations, the backmetal layer may be patterned.

Still referring to FIG. 16, in various implementations the semiconductorpackage 152 may include a mold compound 170. The mold compound 170 maybe coupled to the die 154. In various implementations, the mold compoundmay include, by non-limiting example, an epoxy mold compound, an acrylicmold compound, or any other type of mold compound or protective coveringcapable of hardening and providing physical support and protection to asemiconductor device. In various implementations, the mold compound 170may cover a plurality of sidewalls 172 of the first metal layer 160 anda plurality of sidewalls 174 of the tin layer. In implementations with aplurality of bumps 166, the mold compound may cover a first side 176 anda second side 178 of each bump. In various implementations, a surface180 of the mold compound may be substantially coplanar and level with asurface 182 of the tin layer 162. In various implementations, and as isillustrated by FIG. 16, the mold compound 170 may cover the sides of thedie. Specifically, the mold compound 170 may cover a third side 184 ofthe die 154, a fourth side 186 of the die 154, a fifth side (oriented asgoing into the page in FIG. 16) of the die, and a sixth side (orientedas coming off the page in FIG. 16) of the die. In the implementationillustrated by FIG. 16, the entirety of the sides of the die are coveredby the mold compound 170, however, in other implementations the sides ofthe die 154 may only partially be covered by a mold compound 170, whilein still other implementations the mold compound 170 may not cover thesides of the die 154. In various implementations, a portion of thesecond side 158 of the die may be covered by a mold compound. The moldcompound covering the second side of the die 154 may be the same or aseparate mold compound from the mold compound 170. In suchimplementations, the mold compound 170 may also cover the sides of thebackmetal layer 168 in implementations where the backmetal layer is thesame length as or shorter than the length of the die 154.

Referring to FIG. 17, a cross-section side view of a secondimplementation of a semiconductor package is illustrated. Thesemiconductor package of FIG. 17 may be similar to the semiconductorpackage of FIG. 17, with the difference being that the backside metallayer 190 may extend beyond the length of the die 192 and may becoextensive with the sides/perimeter of the semiconductor package 188.Further, as illustrated by FIG. 17, the backside metal layer 190 mayinclude multiple layers, and in particular implementations, may includethree layers. The backside metal layer may include, by non-limitingexample, a metal or metal alloy including titanium, nickel, silver,vanadium, copper, and any combination thereof. In particularimplementations, the backmetal layer 190 may include a layer includingtitanium, a layer including nickel, and a layer including a silvercopper alloy. In other particular implementations, the backmetal layermay include a layer including titanium, a layer including a nickelvanadium alloy, and a layer including a silver-copper alloy.

Referring to FIGS. 18A-18G, cross-section side views of a semiconductordevice following various steps of an implementation of a method forforming the semiconductor package of FIG. 16 are illustrated. Referringspecifically to FIGS. 18A-18B, a method for forming the semiconductorpackage of FIG. 16 may include forming a plurality of bumps/studs 194 ona first side 196 of a wafer 198. More specifically, the method mayinclude forming a third metal 200 on the first side 196 of the wafer198. The third metal layer 200 may be any metal disclosed herein, and inparticular implementations, may include aluminum. The third metal layer200 may be patterned, as illustrated by FIG. 18A, however, in otherimplementations the third metal layer may not necessarily be patterned.

Referring to FIG. 18B, the method may include forming a first metallayer 202 over the third metal layer 200. The first metal layer 202 maybe any metal disclosed herein, and in particular implementations,includes copper. The first metal layer 202 may be patterned, asillustrated by FIG. 18B, however, in other implementations the firstmetal layer may not be patterned. In various implementations, the methodmay also include forming a second metal layer 204 over the first metallayer 202. The second metal layer 204 may be any metal disclosed herein,and in particular implementations, includes tin. The second metal layer204 may also include a solder material. The second metal layer 204 maybe patterned as illustrated by FIG. 18B, however, in otherimplementations where additional conductive layers cover the secondmetal layer 204, the second metal layer may not necessarily bepatterned.

In various implementations, the method for forming the semiconductorpackage of FIG. 16 includes forming non-patterned metal layers over thefirst side 196 of the wafer 198. The method may then include etchingthrough any number of the metal layers, including all of the metallayers coupled over the first side 196 of the wafer 198, in order toform the plurality of bumps 194. In various implementations, less thanthree metal layers may be coupled over the first side 196 of the wafer198, and in particular implementations, only a single metal layer may beformed and coupled directly to the first side 196 of the wafer 198. Inother implementations, more than three metal layers may be formed overthe first side 196 of the wafer 198. The metal layers coupled to thefirst side 196 of the wafer 198 may be used to form any number of bumpsover the wafer.

Referring specifically to FIG. 18B, the method for forming thesemiconductor package of FIG. 16 may include forming a plurality ofrecesses 206 into the first side 196 of the wafer 198 to a desired depthinto the wafer. In particular implementations, the depth of each recessof the plurality of recesses 206 may be less than 50 um, while in otherimplementations the depth may be 50 or more micrometers depending on thethickness of the wafer. In various implementations, the plurality ofrecesses 206 may be formed using a saw, a laser, a plasma etch, achemical etch, or any other method for forming a recess in a wafer. Inimplementations where an etch is used, the etch may be an etchingprocess marketed under the tradename BOSCH® (the “Bosch process”) byRobert Bosch GmbH, Stuttgart, Germany, may be used to form the pluralityof recesses 206 in the wafer 198. In such implementations, the sidewallsof the plurality of recesses 206 may be slightly patterned or ridgedwhich may facilitate adhesion of a mold compound to the sidewalls of theplurality of recesses 206. In various implementations, the plurality ofrecesses 206 may be positioned in the wafer 198 so that they are betweenthe semiconductor devices in the wafer.

Referring to FIG. 18C, the method for forming the semiconductor packageof FIG. 16 includes applying a mold compound 208 to the first side 196of the wafer 208. The mold compound may include any type of moldcompound disclosed herein and may be applied using, by non-limitingexample, a liquid dispensing technique, a transfer molding technique, avacuum molding technique, a glob top molding technique, or a compressionmolding technique. In various implementations, and as illustrated byFIG. 18C, the mold compound 208 may encapsulate the plurality of bumps194 and fill the plurality of recesses 206. In other implementations,the mold compound 208 may only be applied within the plurality ofrecesses 206 and between the plurality of bumps 194 without flowing overthe outer surfaces 210 of the plurality of bumps 194.

Referring to FIG. 18D, the method for forming the semiconductor packageof FIG. 16 may include thinning a second side 212 of the wafer 198 tothe desired depth of the plurality of recesses 206. In particularimplementations, the method may include backgrinding a second side 212of the wafer 198 to reach the plurality of recesses 206 and singulate aplurality of die 214 from the wafer. In implementations where the secondside 212 of the wafer 198 is background, the backgrinding may use aprocess marketed under the trade name TAIKO by DISCO of Tokyo, Japan.The backgrinding leaves a ring of non-removed material (TAIKO ring)along the perimeter of the wafer which helps to prevent the wafer fromcurling, warping or otherwise bending during processing while at thesame time removing most of the thickness and material of the second side212, or backside of the wafer 198. The ring is then subsequently removedin a separate cutting step prior to singulation of the die. In otherimplementations of methods of forming semiconductor devices the TAIKOprocess may not be used, but some other backgrinding or othermaterial-removal technique may be used, such as removing the materialthrough a wet etch. In various implementations, the thinned wafer 198,or plurality of die 214, may be less than 50 um thick, while in otherimplementations the thinned wafer, or plurality of die, may be 50 ormore um thick. The mold compound 208 coupled to the first side 196 ofthe wafer 198 and within the plurality of recesses 206 may facilitatethinning the wafer 198 by providing structural support to the wafer. Inother implementations, the second side 212 of the wafer may not bethinned to the depth of the desired recesses 206. In this manner, thedie of each semiconductor package may be stepped upon singulating thewafer 198.

Referring to FIG. 18E, the method for forming the semiconductor packageof FIG. 16 may include coupling a backside metal layer 216 to the secondside 212 of the wafer 198 or to the second side of the plurality of die214. The backside metal layer 216 may be any type of metal disclosedherein, and in particular implementations, may include copper. Invarious implementations, the backside metal layer may be coupled to thesecond side of the wafer through an electroplating process. In otherimplementations, the backside metal layer may be coupled to the secondside of the wafer through a sputtering process or an electroplatingprocess. In still other implementations, the backside metal layer may bea metal frame/film coupled to the wafer through, by non-limitingexample, sintering, soldering, or fusion bonding. In variousimplementations, the backside metal layer 216 may be a thick backsidemetal layer and in particular implementations, may be as thick as orthicker than the thinned wafer 198. In various implementations, themethod for forming the semiconductor package of FIG. 16 may includeforming a plurality of openings 218 in the backside metal layer 216. Inother implementations, the backside metal layer 216 may not include anyopenings therein. In implementations where a plurality of openings 218are formed in the backside metal layer 216, the method may include,though not illustrated, applying a second mold compound to the secondside 212 of the wafer 198 that fills the plurality of openings 218. Thesecond mold compound may be the same as or different from the first moldcompound 208. In various implementations, the second mold compound mayalso encapsulate the backside metal layer 216. In such implementations,the method may include backgrinding the second mold compound to exposethe backside metal layer. In implementations with the second moldcompound applied to the second side 212 of the wafer 198, the entiretyof the die of the singulated semiconductor may be at least partiallycovered by a mold compound on all six sides of the die. Inimplementations where the second side 212 of the wafer 198 is backgroundusing the Taiko process, the Taiko ring may be removed after thebackside metal is coupled to/formed on the second side of the waferusing a separate singulation process.

Referring to FIG. 18F, the method for forming the semiconductor packageof FIG. 16 may include exposing the outer surface 210 of the pluralityof bumps 194 through the mold compound 208 by grinding the mold compound208. In various implementations, only the mold compound may be grounduntil it is coextensive with the surface 210, however, in otherimplementations the mold compound and a portion of the plurality ofbumps 194 may be ground together. In this manner, the method may includeplanarizing the outer surface 210 of the plurality of bumps 194 with theouter surface 220 of the mold compound 208. The backmetal layer 216 mayfacilitate the thinning of the mold compound 208 by adding structuralsupport to the wafer 198 and the plurality of die 214. In variousimplementations, and as illustrated by the order of FIGS. 18C-18F, thesecond side 212 of the wafer 198 may be thinned before the mold compound208 is ground to expose the plurality of bumps 194, however, in otherimplementations the method may include grinding the mold compound 208 toexpose the plurality of bumps before the second side 212 of the wafer198 is thinned.

Referring to FIG. 18G, the method for forming the semiconductor packageof FIG. 16 includes singulating the mold compound 208 through theplurality of recesses 206 into a plurality of semiconductor packages221. The mold compound may be singulated using a saw, a laser, a plasmaetch, water jet cutting, a chemical etch, or any other method forcutting or removing mold compound. In various implementations, thesingulation line (or the width of the cut/etch made to singulate themold compound) may be less wide as compared to the width of each recessof the plurality of recesses 206. In such implementations, the sidewallsof each die of the plurality of semiconductor packages may be covered bythe mold compound 208. In implementations where the backside metal isnot patterned, the backside metal may be singulated along with the moldcompound to form the plurality of semiconductor packages.

Referring to FIGS. 19A-19C, cross-section side views of a semiconductordevice after steps of an implementation of a method for forming thesemiconductor package of FIG. 17 are illustrated. Referring specificallyto FIG. 19A, the method for forming the semiconductor package of FIG. 17may be similar to the method illustrated in FIGS. 18A-18G, with thedifference being that the method may include coupling a backside metallayer 222 to the second side 224 of the wafer 226 (or coupling abackside metal layer to a second side of the plurality of die), with thebackside metal layer including multiple backside metal layers. In theimplementation illustrated by FIG. 19A the method includes coupling abackside metal layer 222 which includes three different backside metallayers. In various implementations, the backside metal layer 222 mayinclude more than or less than three backside metal layers.

Each layer of the backside metal layer may be deposited to the waferthrough, by non-limiting example, a sputtering or evaporation technique.In various implementations, the backside metal layer may include, bynon-limiting example, titanium, nickel, silver, copper, vanadium, or anyother metal. In particular implementations, the backside metal layer mayinclude a titanium layer, a nickel layer, and a silver-copper layer. Inother particular implementations, the backside metal layer may include atitanium layer, a nickel-vanadium layer, and a silver-copper layer. Invarious implementations, and as illustrated by FIG. 19A, the backsidemetal layer 222 may be patterned or may not be patterned.

Referring to FIG. 19B, the method for forming the semiconductor packageof FIG. 17 may include exposing the plurality of bumps 228 through themold compound 230 by grinding the mold compound. The plurality of bumpsmay be exposed using the same method or a similar method as describedabove in relation to FIG. 18F.

Referring to FIGS. 19A and 19C, the method for forming the semiconductorpackage of FIG. 17 includes singulating the mold compound 230 throughthe plurality of recesses 232 and the backside metal layer 222 into aplurality of semiconductor packages 234. The mold compound 230 and thebackside metal layer 222 may be singulated using any method disclosedherein. As the backside metal layer is not patterned, the sidewalls ofthe backside metal layer may be coextensive with the sides of therespective semiconductor packages 234.

The methods for forming semiconductor packages disclosed herein mayallow for the formation of thin die without needing a dual metallizationprocess for the purpose of stress balance. The mold compound and thebackside metal layer may offer the necessary support needed to handlethe thinned die and wafer during formation of the semiconductorpackages.

Referring to FIG. 20, an implementation of a semiconductor package 236is illustrated that is similar to package implementations alreadydisclosed in this document. However, in this implementation, the package236 includes electrical contacts 238, 240 that include a pad layer 242,a plated metal layer 244, and a solder resist layer 246. The electricalcontacts 238, 240 extend through openings 248, 250 in an organicmaterial 252. In the implementation illustrated, the organic material252 is a mold compound, which may be any mold compound disclosed in thisdocument. In this implementation, the height of the electrical contacts238, 240 is higher/longer than in the other electrical contactimplementations disclosed in this document. In this implementation, thelayer that increases the height of the electrical contacts 238, 240 isthe solder resist layer 246. However, in other implementations, thethickness/height of the plated metal layer 244 may be increased throughincreased plating of metal to increase the height of the electricalcontacts 238, 240.

The effect of increasing the height of the electrical contacts throughchanging the predetermined height of the formed portion of theelectrical contacts 238, 240 is that the resulting semiconductor packagehas increased structural support, particularly where the semiconductordie 254 is thinned. Any of the thinned semiconductor die disclosedherein may be utilized in various package implementations. In particularimplementations, the thickness of the thinned semiconductor die 254 maybe between about 0.1 microns to about 125 microns. As the length of theelectrical contacts 238, 240 lengthens, the combination of the materialof the electrical contacts and the organic material 252 providesadditional structural support to the die, which in variousimplementations may reduce a warpage of the thinned semiconductor die254. In particular implementations, the warpage may be less than 25microns; in others, the warpage may be less than 50 microns; in stillothers, the warpage may be less than 75 microns, and in yet otherimplementations, the warpage may be less than 200 microns. The length ofthe electrical contacts 238, 240 is determined in variousimplementations to determine the desired warpage of the particularthinned die being used.

In various implementations, the warpage may be measured using varioustechniques. For example, a capacitative scanning system with two probesthat utilize changes in the capacitance for each probe when a die orwafer is inserted into the gap between the probes to determine a waferthickness and/or position can be utilized to map the warpage of a die orwafer. An example of such a capacitive system that may be utilized invarious implementations may be the system marketed under the tradenamePROFORMA 300ISA by MTI Instruments Inc. of Albany, N.Y. In otherimplementations, the warpage may be measured by a laser profilometerutilizing confocal sensors marketed under the tradename ACUITY bySchmitt Industries, Inc. of Portland, Oreg. In other implementations,any of the following shape/profile measurement systems marketed byKeyence Corporation of America of Itasca, Ill. could be employed tomeasure die or wafer warpage: the reflective confocal displacementsensor system marketed under the tradename CL-3000, the 2D laserprofiling system marketed under the tradename LJ-V7000, or the 3Dinterferometric sensing system marketed under the tradename WI-5000.

In various implementations, solder resist may not be used and the entirematerial of the electrical contact besides the pad may be made of platedmetal. In other implementations, however, the metal layer(s) besides thepad material may be formed using, by non-limiting example,electroplating, electroless plating, evaporating, sputtering, soldering,screen printing, silver sintering, sintering, any combination thereof,or any other method of forming a metal-containing material into anelectrical contact.

The various methods of forming electrical contacts disclosed in thisdocument may be employed to form electrical contacts with lengthenedformed portions through choosing those process parameters for theparticular metal-containing material process that will allowdeposition/forming of the metal-containing material to the desiredheight to create the desired structural support and/or warpage of thesemiconductor die/semiconductor package. In particular implementations,a method of forming a semiconductor package includes providing asemiconductor substrate like any disclosed herein that includes aplurality of semiconductor die like any disclosed herein where thesemiconductor substrate includes a first side and a second side. Themethod includes forming a plurality of electrical contacts on the firstside of the semiconductor die through forming at least a portion of theplurality of electrical contacts to a predetermined height where theplurality of electrical contacts are coupled with the plurality ofsemiconductor die. The method also includes applying an organic materiallike any disclosed herein to the first side of the semiconductor diewhere the one or more electrical contacts extend into one of moreopenings in the organic compound. In various implementations, becausethe organic compound is applied over the electrical contacts, theelectrical contacts themselves form the openings in the organiccompound. The method also includes leveling the organic material with asurface of the plurality of electrical contacts. In variousimplementations, as disclosed herein, the process of leveling includesgrinding/polishing the organic material down to the level of the top ofthe plurality of electrical contacts. In other implementations, theprocess of leveling may occur in a curing/reflowing process where theorganic material flows around the plurality of electrical contacts untilit reaches the level of the upper surfaces of the electrical contacts attheir predetermined height. Following leveling of the organic material,the plurality of semiconductor packages may then be singulated one fromthe other using any singulation method disclosed herein. In variousmethod implementations, additional grooving, thinning, backmetal formingand other steps like those disclosed herein may be utilized and selectedusing the principles disclosed herein.

Referring to FIG. 21, an implementation of a semiconductor package 256with a slug 258 coupled thereto is illustrated. In this implementation,the slug 258 is coupled to one of the electrical contacts 260 of thepackage 256. In other implementations, however, slugs may be coupled toboth electrical contacts 260, 262 of the package 256. The slug 258 maygenerally be used to support wirebonding to the electrical contact 260and not in flip chip bonding packaging operations. The material of theslug 258 may also permit the thickness of the semiconductor die 264 tobe made very thin—toward the lower ends of the thickness rangesdisclosed herein while permitting wirebonding to be successfully carriedout. In various implementations, the slug 258 may also assist thepackage with handling electrical surge and other electrical capacityneeds during operation. A slug 258 may be utilized in packages wherebackmetal 266 is applied in one or more layers to the thinnedsemiconductor die 264, or in packages where no backmetal is utilized.Any of the metal layers, metal types, and methods of forming the metallayer(s) of the electrical contacts disclosed in this document may beemployed in various implementations. In various implementations, theslug 258 may include copper.

Referring to FIG. 22, another implementation of a semiconductor package268 is illustrated. In this implementation, a slug 270 is coupled to asecond side 272 of the thinned semiconductor die 274. In this case, theslug 270 is attached to backmetal layers 276 formed on the second sideof die 274. In this package implementation, bumps/stud bumps/pillars278, 280 are coupled to electrical contacts 282, 284, respectively. Thisparticular package implementation 268 is designed to be bonded using aflip chip process and then wirebonded to slug 270 on the backside/second side 272 of the package.

In the implementations of semiconductor packages 256, 268 of FIGS. 21and 22, semiconductor die of any of the thicknesses disclosed herein maybe utilized, along with any of the organic materials disclosed herein,and any of the metal-containing layers and metals disclosed herein.

In various method implementations, no precut or partial grooving betweenthe plurality of die of a semiconductor substrate may be carried outprior to the application of an organic compound. Where the plurality ofdie will be thinned, the depth of the die/saw streets/scribe linesthemselves may be sufficient to carry out the various methods of formingsemiconductor packages disclosed herein. For example where asemiconductor substrate will be thinned to about 10 microns, the about 5micron depth of the die streets into the material of the substrate/dieresulting from the processing steps that form the separate semiconductordie suffices to act as the equivalent of any partialgrooving/precutting. FIG. 23A illustrates a semiconductor substrate 286with a plurality of semiconductor die 288 with die streets 290 betweenthe plurality of semiconductor die 288. Die pads 292 are formed as partof semiconductor die 288. FIG. 23B illustrates the substrate 286following formation of electrical contacts 292 using any of the methodsof forming electrical contacts disclosed herein.

FIG. 23C illustrates the semiconductor substrate 286 implementationfollowing application of organic material 291 over the electricalcontacts 292 which fills the die streets 290. FIG. 23D illustratessemiconductor substrate 286 following a thinning process that singulatesthe plurality of semiconductor die 288 at the die streets 290. Thethinning process may be carried out using any methods and process ofthinning disclosed in this document. FIG. 23E illustrates the pluralityof semiconductor die 288 following application of backmetal 294 whichhas been patterned to correspond with each of the plurality ofsemiconductor die 288. Any of the methods and processes for formingbackmetal disclosed herein may be employed in various methodimplementations. In other implementations, however, the backmetal maynot be formed. Referring to FIG. 23F, the plurality of die 288 areillustrated following leveling of the organic material 291 with thesurface of the electrical contacts 292. As illustrated, slugs 296 havealso been coupled to the electrical contacts 292. In variousimplementations, the slugs 296 may be formed through a photoresist,screen printing, or stencil printing pattering andelectroplating/electroless plating process. In other implementations,the slugs 296 may be adhered to the electrical contacts 292 using abonding material. In other implementations, the slugs 296 may be coupledto the electrical contacts 292 through a sintering process, such as, bynon-limiting example, a silver sintering process or other sinteringtechnique in various implementations. The slugs may include any of awide variety of metal containing materials, including, by non-limitingexample, metal foil, metal film, copper, copper alloys, or any othermetal-containing material. FIG. 23G illustrates the plurality of die 288following a singulation process through the organic material 291 thatleaves the sidewalls of the die covered at least partially by theorganic material like those package implementations disclosed herein.Any of the singulation methods and systems disclosed herein may beemployed in various method implementations.

Referring to FIGS. 24A-C, another semiconductor substrate 298 isillustrated as various steps in an implementation of a method of formingsemiconductor packages. FIG. 24A illustrates the substrate 298 followingthinning and singulation of the plurality of die 300, formation ofelectrical contacts 302, leveling of organic material 301, andapplication of backmetal layers 304. Bumps/stud bumps/pillars 306 havealso been coupled to the electrical contacts 302 through, bynon-limiting example, pattering and plating, ball drop, ball bonding, orany other method of forming/attaching a ball/pillar/stud to anelectrical contact. FIG. 24B illustrates the substrate 298 of FIG. 24Aafter coupling of slugs 308 to the backmetal layers 304. FIG. 24Cillustrates the plurality of die 300 following singulation of thesemiconductor packages using any singulation technique disclosed herein.A wide variety of method implementations involving the formation andattachment of slugs to electrical contacts may be employed using theprinciples disclosed herein.

In places where the description above refers to particularimplementations of semiconductor packages and implementing components,sub-components, methods and sub-methods, it should be readily apparentthat a number of modifications may be made without departing from thespirit thereof and that these implementations, implementing components,sub-components, methods and sub-methods may be applied to othersemiconductor packages.

What is claimed is:
 1. A semiconductor package, comprising: asemiconductor die comprising a first side and a second side, the firstside of the semiconductor die comprising one or more electricalcontacts; an organic material covering at least the first side of thesemiconductor die, wherein the one or more electrical contacts extendthrough one or more openings in the organic material; a metal-containinglayer coupled to the one or more electrical contacts; and one or moreslugs coupled to one of the first side of the semiconductor die, thesecond side of the semiconductor die, or both the first side of thesemiconductor die and the second side of the semiconductor die.
 2. Thepackage of claim 1, wherein the organic material is directly coupled tofive sides of the semiconductor die.
 3. The package of claim 1, whereinthe one or more electrical contacts comprise a bump coupled to a die padcoupled to the first side of the semiconductor die.
 4. The package ofclaim 1, wherein the organic material is a mold compound.
 5. The packageof claim 1, wherein the metal-containing layer is a solder resist layer.6. The package of claim 1, wherein the semiconductor die comprises athickness between 0.1 microns and 125 microns.
 7. The package of claim1, wherein the one or more electrical contacts are one of bumps orstuds, the second side of the die further comprises a backmetal, and theone or more slugs are coupled to the backmetal.
 8. A semiconductorpackage, comprising: a semiconductor die comprising a first side and asecond side, the first side of the semiconductor die coupled to one ormore electrical contacts; an organic material covering at least thefirst side of the semiconductor die, wherein the one or more electricalcontacts extend through one or more openings in the organic material; ametal-containing layer comprised in the one or more electrical contacts;and one or more slugs directly coupled to the metal containing layer. 9.The package of claim 8, wherein the metal-containing layer is a solderresist layer.
 10. The package of claim 8, wherein the one or moreelectrical contacts comprise a bump coupled to a die pad coupled to thefirst side of the semiconductor die.
 11. The package of claim 8, whereinthe organic material is a mold compound.
 12. The package of claim 8,wherein the semiconductor die comprises a thickness between 0.1 micronsand 125 microns.
 13. The package of claim 8, wherein the organicmaterial is directly coupled to five sides of the semiconductor die. 14.A semiconductor package, comprising: a semiconductor die comprising afirst side and a second side, the first side of the semiconductor diecoupled to one or more electrical contacts; an organic material coveringat least the first side of the semiconductor die, wherein the one ormore electrical contacts extend through one or more openings in theorganic material; a metal-containing layer coupled to the one or moreelectrical contacts; one or more backmetal layers coupled to the secondside of the semiconductor die; and one or more slugs directly coupled tothe one or more backmetal layers.
 15. The package of claim 14, whereinthe metal-containing layer is a solder resist layer.
 16. The package ofclaim 14, wherein the one or more electrical contacts comprise a bumpcoupled to a die pad coupled to the first side of the semiconductor die.17. The package of claim 14, wherein the organic material is a moldcompound.
 18. The package of claim 14, wherein the semiconductor diecomprises a thickness between 0.1 microns and 125 microns.
 19. Thepackage of claim 14, wherein the organic material is directly coupled to5 sides of the die.
 20. The package of claim 14, wherein the one or morebackmetal layers comprise three backmetal layers.